Plumbing a Double Kitchen Sink


Installing a double kitchen sink can save time and effort by simultaneously accomplishing two tasks at once, but improper installation could cause plumbing issues that require costly repairs.

Install a wye to direct waste from both sinks into one drain line to prevent clogs and bad smells from developing. This will also help avoid costly plumbing repair bills in the future.


A double kitchen sink provides more workspace by enabling two people to wash dishes and prepare food at the same time. Installation requires more plumbing work than with single sink setups, yet can still be relatively straightforward. First, turn off all hot and cold isolation valves beneath your sink to prevent water flow during setup.

A P-trap, named for its U-shape curve, is an essential component of your sink’s drain system. It acts as a powerful barrier that keeps sewer gases and odors from seeping into your home, while its curve also traps food debris that would otherwise enter into main drainage pipes.

P-traps are usually constructed out of either brass or polypropylene material. While brass P-traps may look appealing at first, with repeated use, they become susceptible to corrosion and will eventually need replacing. Polypropylene p-traps, on the other hand, are more durable, less likely to react with acidic foods, easier to clean, and often come included with kitchen drain trap kits as both parts. Before installing a new P-trap, make sure your drain outlet pipe can accommodate its tailpiece and sanitary tee.


A double-sink setup is a popular choice among many homeowners. It enables them to wash dishes on one side while simultaneously preparing food on the other, yet can cause plumbing issues if improperly plumbed, such as restricted water flow, clogs, or leaks. If any such problems arise, they must contact a plumber immediately so as to solve these problems quickly.

An illustrated kitchen sink plumbing diagram can help you assess what needs to be done. The diagram will explain how components are connected and laid out – essential information for installation or troubleshooting purposes – while also showing where drain pipes and vent pipes are situated.

Before beginning, ensure the water supply valves located under your sink are off. This will prevent accidental leakage. Dry-assemble the faucets and connect hot and cold water lines to their respective isolation valves – then proceed with plumbing connections.

Sanitary tee

Installing a double sink requires using appropriate plumbing fittings that will maintain optimal flow velocities while decreasing blockages. There are various kinds of pipe fittings, including sanitary tees and combo wyes, that may help.

Sanitary Tees are T-shaped pipe fittings used to connect branch lines to vertical drain or vent pipes, as well as provide drainage or ventilation of wastewater from within a building. Straight or reduced models with various diameters to fit multiple pipe sizes are available – as are different materials with differing corrosion-resistance levels.

Step one in setting up a double kitchen sink involves installing the sanitary tee. Next, connect both sink drain spouts to both short ends of the “tee,” plumb them together, then fasten a plumbing line trap to its lower part (not yet explored) as soon as connections have been made. After that’s complete, it’s time to test for leaks. Once that test is finished, turn on the hot and cold isolation valves under your sink for inspection purposes, and turn them back off once they’re complete!

Basket strainers

A double kitchen sink allows you to simultaneously perform several tasks, like washing dishes and preparing food, while saving space by eliminating the need for a dishwasher. However, plumbing a double sink setup is more complex than exploring one single sink because a tee fitting must connect two drain assemblies; additionally, a strainer basket must be placed over both drain assemblies in order to avoid clogging issues.

The ideal sink strainers feature an easy-to-use spin lock or twist-and-drop stopper with spin-locking capabilities, making them suitable for everyday use in both home improvement stores and department stores.

Before installing a filter, apply the plumber’s putty around the edge of the sink to prevent leaks or silicone caulk from forming a watertight seal once this has dried, screw on a back nut strainer onto your drain tailpiece with its rubber gasket and paper washer attached, along with placing any necessary caps or covers over its openings.

Vent pipe

A plumbing vent pipe allows air to circulate freely through drains, relieving the pressure that could otherwise build up and lead to clogs or foul odors. Furthermore, it prevents sewer gases from entering homes or buildings – especially important in commercial settings where occupants may not recognize the risks posed by such gases.

Whenever your drains appear to be clogged or make strange sounds, it may be due to an obstruction in the vent stack that needs cleaning. Furthermore, it would be prudent to have it checked if there is a sulfurous smell emitting from them.

Vent stacks are pipes designed to connect multiple sink and fixture vents in one home or building. Constructed of PVC, their size depends on local plumbing codes as well as how many fixtures they serve; installation can either be horizontal or vertical, with sloped installation required so air can freely move through it. As alternatives, loop vents and air admittance valves (AAV), commonly referred to as studs or vents, work similarly, while loop vents do not.